KnowledgeBoat Logo
|

Mathematics

The value of :

cos2 60° - 2 sin3 30° + 3 cot4 45° is :

  1. 1

  2. -2

  3. 3

  4. 2

Trigonometric Identities

12 Likes

Answer

cos260°2sin330°+3cot445°=(12)22×(12)3+3×(1)2=142×18+3=1414+3=3\text{cos}^2 60° - 2 \text{sin}^3 30° + 3 \text{cot}^4 45° = \Big(\dfrac{1}{2}\Big)^2 - 2 \times \Big(\dfrac{1}{2}\Big)^3 + 3 \times (1)^2\\[1em] = \dfrac{1}{4} - 2 \times \dfrac{1}{8} + 3\\[1em] = \dfrac{1}{4} - \dfrac{1}{4} + 3\\[1em] = 3

Hence, option 3 is the correct option.

Answered By

3 Likes


Related Questions